Susan from 500.co has enough to say about e-mail marketing for startups. That's why she made this cool set of templates.
Ultimate Email Playbook for Startups is a good way to start preparing your e-mail marketing campaign. It contains a bunch of welcome-letters examples, as well as trigger e-mails and some great examples of e-mail copy.
Shared this book, because I believe that it's must read for everyone who are involved in creating startups.
CRXExtractor Band